CONTENTS 10 COMMON QUESTIONS ABOUT AUTOMATIC EVOLUTION OF FIRE STREAMS.......................................................2 NOZZLES EVOLUTION OF COMBINATION NOZZLES......................................3 1) How is an automatic nozzle different from a regular (conventional) UNDERSTANDING FIRE NOZZLE DESIGN ......................................5 nozzle? LIMITATIONS OF CONVENTIONAL NOZZLES.................................6 2) How does an automatic nozzle work? AUTOMATIC NOZZLES INVENTED................................................ 10 3) What pressure do we pump to automatic nozzles? BENEFITS OF AUTOMATIC NOZZLES .......................................... 13 4) How do I know how much water I am flowing? SLIDE VALVE vs. BALL VALVE ..................................................... 16 5) What is the flow from each "Click Stop" on the nozzle? TRAINING CONSIDERATIONS WITH AUTOMATICS .................... 18 6) Can I use automatics with foam and foam eductors? USING LARGER SIZE ATTACK LINES .......................................... 21 7) Why don't all automatic nozzles have spinning teeth? 8) What type of nozzle is best for “Nozzleman Flow Control?” BOOSTER TANK OPERATIONS..................................................... 22 SHAPING THE FIRE STREAM PATTERN ...................................... 23 9) Is it true that the stream from a "SOLID" bore nozzle hits harder and goes farther than the "Hollow”' stream from a fog nozzle? SMOOTH BORE vs. FOG TIP .......................................................... 24 FLUSHING DEBRIS.......................................................................... 28 10) What's all this talk about low pressure nozzles? What are the trade offs, is the compromise worth it? NOZZLE REACTION ........................................................................ 29 DUAL-FORCE/MID-FORCE ............................................................. 34 Upon completion of this training booklet, you will be able to answer AUTOMATIC NOZZLES & FOAM.................................................... 37 these, and many other, questions pertaining to firefighting nozzles. MASTER STREAM AUTOMATICS .................................................. 40 The ten questions and complete answers are listed in the appendix. THE WATER TRIANGLE CONCEPT ............................................... 42 CONCLUSION................................................................................... 44 LITERATURE 24/7 – Email or Fax .................................................. 45 APPENDIX ........................................................................................ 46 FRICTION LOSS COEFFIEIENTS.................................................... 58 FLOW AND REACTION CHARTS ................................................... 61 1 EVOLUTION OF FIRE STREAMS EVOLUTION OF THE COMBINATION NOZZLE (FOG NOZZLE) 17th Century (Bucket Brigades) The combination nozzle used today in the North Leather buckets were passed from person to person forming American fire service is a simple variation of the straight a line from the supply source to volunteers positioned near stream nozzle of the late nineteenth and early twentieth the fire. The water was applied, by the volunteers, in the best centuries. A standard smooth bore nozzle gives little in the way they could. way of stream choices. One diameter, one flow... @ 50 psi. 18th Century (Hose Companies) Leather hose and copper/brass playpipes. Sewn leather hose gave way to copper riveted hose. 1700's 19th Century (Engine & Hose Companies) 2.5" Cotton Hose & Underwriters Pipe (1888). To change streams required changing nozzle size. 20th Century 40's & 50's: 1.5" hose and assorted water spray nozzles. 50's & 60's: 1.5" hose combination, fixed and adjustable gallonage nozzles. 1800's 60's & 70's: 1.5" & 1.75” hose, automatic nozzle introduced The Introduction Of Stacked Tips by C.H. McMillan. Allowed Quick Accessibility To Four Tip Sizes 70's & 80's: 1.75" & 2.0" hose, wide spread acceptance of The Addition of a Baffle (disc) added two features: automatic nozzles. 1) Flow Adjustment 80's & 90's: Light weight 1.75" & 2.0" hose and introduction of dual pressure nozzles and special application attachments. 1940's & 50's 21st Century Lightweight 2.5” & 3.0” hose and introduction of safe, offensive portable monitor. The Baffle space changes for different gallonage. 3 2 UNDERSTANDING FIRE NOZZLE DESIGN The purpose of any nozzle is to provide a restriction of the flow to build pressure. This restriction, and subsequent 1940's & 50's created pressure, provides a usable velocity to project the water stream. For any one flow, there is one correct nozzle size (restriction) to develop the optimum pressure and velocity. Nozzles come in a confusing number of sizes, shapes and styles. The large number of combinations greatly increases the possibility of hydraulics problems being Flow is determined by how far the baffle (disc) is from the encountered on the fireground. circular opening. The distance is preset in fixed gallonage combination nozzles and is changeable in adjustable gallonage nozzles. 2) Pattern Adjustment 1940's & 50's Fig. 7 SMOOTH BORES: • Fixed opening sized from 1/2" to 1-1/4" for handline firefighting operations • Larger stream (GPM) sized from 1-1/4" to 2" Moving the shaper back widens the pattern. • For each flow, there is ONE CORRECT nozzle size to develop optimum velocity and reach FOG NOZZLES: • Fixed or very limited gallonage selections • Require adjustments that limit nozzle performance 1940's & 50's • Require correct pump discharge pressure for best performance and GPM delivery DESIGNED NOZZLE PRESSURES Smooth Bore Nozzle - Handline - 50 PSI Moving the shaper forward focuses the water and a tight Smooth Bore Nozzle - Master Stream - 80 PSI solid stream can be achieved. Fog Nozzle (all types) - 100 PSI 4 5 Current conventional nozzles ("conventional" refers to a correct nozzle pressure, the proper flow (GPM), determined nozzle with a fixed size opening or manually adjustable by the correct pump discharge pressure, must be supplied opening) come in two basic types: 1. smooth bore and 2. (Fig. 9). peripheral jet, more commonly known as fog nozzles (Fig. 8). To allow for changing water conditions and to add greater flexibility (and often confusion), smooth bore nozzles are also available with stacked tips of increasing size. Fig. 9 These flow requirements must include consideration of the available water supply, hose size and length, and the pumping capability of the supplying engine. IF all things go right, a given flow of water passes through the nozzle to produce the desired nozzle pressure and stream. A big IF!!! If the proper fire stream is attained, the flow to that nozzle cannot be altered unless the discharge opening is changed Fig. 8 (manually adjusted) for the new flow, with a corresponding adjustment in pump discharge pressure. Since conventional Many fog nozzles, booster through master stream, nozzles cannot change size, or are very limited in operate similar to a stacked tip by use of a gallonage ring adjustment, one of two things must happen. that manually adjusts the discharge opening (restriction) of the nozzle. Though manually adjusted tips improve the When a conventional nozzle is supplied less than the situation over fixed sizes (smooth bores), maximum rated flow, the result is a weak, less effective, stream. This efficiency is not achieved. Complete coordination between situation may be due to poor water supply, long hose lays, the pump operator, supplying the correct pump discharge improper selection of tip size, or pump operator error (Fig. pressure, and the nozzle operator is normally impossible. 10). This under-pressured stream may waste water, because Will the pump operator pump to a predetermined setting? If the velocity needed to reach the seat of the fire is not so, is the nozzle actually set to that position? Has the nozzle produced. This under pressure stream may cause the hose operator made a change in the setting, assuming that it will to kink more easily, therefore, reducing the flow even more! change the flow delivered? The problems multiply! It may jeopardize the safety of the nozzle crew. Little, if any, knockdown capability is achieved. Poor water supplies are LIMITATIONS OF CONVENTIONAL NOZZLES often blamed for poor fire streams. More often, poor streams result from the inability to match the correct nozzle In order for a conventional nozzle with a fixed opening size to the water supply that is available! (either smooth bore or fog) to operate at the 6 7 Fig. 10 On the other hand, if more than the required flow is being delivered to the conventional nozzle, excessive nozzle pressure will result (Fig. 11). This excessive flow will produce a proportionally higher nozzle pressure and, therefore, a corresponding increase in reaction, or "kickback". Chart A Any attempt to control the over-pressured line, by the nozzle operator cutting back at the nozzle, results in a fire stream that is broken and erratic. A partially open ball valve Fig. 11 creates tremendous turbulence which reduces the stream's effectiveness. The nozzle crew must make a decision; fight The higher nozzle reaction will make the hose line more the hose line and the fire, or fight the fire with a broken, ineffective, stream. difficult to handle. It may jeopardize the safety of the nozzle crew in an environment that is already unsafe. This dramatic It becomes obvious when a handline is over pressurized. difference in nozzle pressure can be shown graphically